The invention relates generally to a gyratory or cone crusher and more particularly to an arrangement for driving a gyratory crusher head of a gyratory or cone crusher.
Gyratory crushers or cone crushers are characterized by cone-shaped crushing heads which are supported to undergo gyratory motion. A crusher head of a gyratory crusher is centered generally about a vertical central axis through the crushers. The gyratory or gyrating motion of the crusher head performs a material comminution action on material as the material moves downward through a space between the head and an inner surface of a concave or bowl-shaped stationary member. The bowl-shaped member or concave is disposed in an inverted position generally over the cone-shaped crushing head. The bowl-shaped member is centered on the vertical central axis of the crusher and has an upper opening through which materials, such as rock, ore, coal or the like are fed into the space between the crushing head and the stationary, bowl-shaped member. The action of the crusher typically distributes the materials annularly about the crushing head. The materials typically move by gravity through the annular space between the inner wall of the stationary bowl member and the outer, cone-like surface of the crushing head. The annular space between the bowl member and the crushing head is also referred to as the crushing chamber. The gyration of the crushing head causes the space at any specific radial position of the crusher to cyclically increase and decrease in size.
State of the art gyratory crushers are generally driven by a horizontally disposed countershaft which radially extends into a lower part of a generally cylindrical crusher housing. An inner end of the countershaft is coupled through a pinion and ring gear to an eccentric bushing or eccentric element to rotatably drive the eccentric element. The eccentric element, in turn, is generally coupled to a connecting shaft of the crusher head to bring about a desired gyratory motion.
A known, but generally accepted, disadvantage of the described gyratory drive arrangement via the countershaft is that crushed materials and the crusher drive share common space in the lower part of the crusher housing. The crushed materials exit through a lower end of the crusher housing, thereby all crushed materials pass peripherally about the drive coupling to the crusher head. Thus, crushed debris accumulates on protective covers of the drive train. As long as no maintenance is required on the crusher, the drive train position in the lower part of the crusher housing may be acceptable. However, the dust and debris which builds up on external crusher drive surfaces coupled with a general inaccessibility of the drive elements in the lower portion of the crushers makes it difficult to maintain the drives of gyratory crushers.